Do biotin supplements actually help with hair growth? Experts weigh in.

For those in search of growing strong, healthy nails and thick, full hair, can biotin supplements actually offer a solution to common beauty concerns?

Biotin deficiency is a relatively uncommon condition, and the vast majority of people can get enough biotin (also known as vitamin B7) just from eating a well-rounded, balanced diet, per Healthline.

With proponents of biotin supplements touting their potential benefits for hair, nails and more, it’s only natural for us to wonder: How necessary are biotin supplements, and do they offer benefits for some people more than others?

We asked the experts to break down what you need to know about biotin.

What does biotin do?

Biotin supports several functions in the body, including the metabolism of carbs, fats and proteins, says Dr. Misbah K. Keen, MD, MBI, MPH, a professor of family medicine at the University of Washington School of Medicine.

Biotin also plays an important role in supporting the structure of keratin, a protein that’s essential to the maintenance of healthy hair, skin and nails, Keen tells USA TODAY.

During pregnancy, biotin is an essential nutrient that supports the growth of the embryo, per Mount Sinai.

Who is at risk for biotin deficiency?

It’s important to understand that most people can satisfy their need for biotin just from eating a variety of biotin-rich foods — think eggs, seeds, nuts, meat and fish, says Dr. Barbara Bawer, a family medicine physician at The Ohio State University Wexner Medical Center.

Biotin deficiency is very uncommon, but experiencing it can cause an array of side effects, including: hair thinning or loss, brittle nails, a red scaly rash (around the eyes, nose, and mouth), a swollen, painful tongue, neurological changes (such as numbness and tingling), and mental health changes (including depression and lethargy), Keen says.

A very small group of people are born without the enzyme biotinidase. This is an inherited condition that impacts an individual’s biotin metabolism, says Dr. Lidya Bal, MD, a physician with Stamford Health. Global estimates approximate that biotinidase deficiency ranges anywhere from one in 40,000 people to one in 60,000 people, per NCBI.

Though rare, there is an elevated risk for people who are pregnant or breastfeeding to experience biotin deficiency. As for why this may occur, during pregnancy, your body metabolizes biotin faster, Bawer explains. When breastfeeding, “you tend to excrete more biotin and therefore are at higher risk of being low,” she says.

Individuals with chronic alcoholism, and people taking long-term antiseizure medications, are also at risk for biotin deficiency, Keen adds. “These can interfere with biotin metabolism or absorption,” he says.

Who benefits from biotin supplements?

“Biotin supplements are used to prevent or treat biotin deficiency,” and individuals with a biotin deficiency may benefit from taking them, says Bal.

Biotin supplements should always be taken under medical supervision, underscores Dr. Sarah Hemeida, MD, MPH, an assistant professor and family physician at UT Southwestern Family Medicine Department and the co-director of Empowher Health, a women's health education program focused on dispelling cultural misinformation.

The adequate intake (AI) for biotin is 30 micrograms a day for adults and eight to 12 micrograms a day for children, Bal says. However, depending on the patient and the severity of their biotin deficiency, dosages will vary. For example, in certain cases, treatment could require taking a dosage of biotin supplements as high as 10mg per day, Bal notes.

Biotin supplements may offer benefits during pregnancy and times of lactation, when it’s especially important to maintain healthy biotin levels, Hemeida says. There are risks to taking biotin supplements during pregnancy, so always consult your doctor first, she recommends.

Does biotin increase hair growth?

Unfortunately, for most people, taking biotin supplements will probably not make much of an impact on hair growth. “Although biotin is widely marketed for hair loss, the evidence supporting its effectiveness is mixed,” Keen says.

According to a 2017 review, some studies have shown biotin supplementation had positive outcomes for hair growth in individuals who had an acquired or inherited deficiency in biotin. However, these cases are still relatively uncommon.

In healthy individuals who aren’t deficient in biotin, biotin supplementation will likely have no effect on hair growth, the same review concluded.

Does biotin support nail health?

Some small clinical trials have shown biotin supplements may help strengthen brittle nails by improving their firmness, thickness and hardness.

However, biotin supplements will likely have no strengthening effect on your nails if you aren’t deficient in biotin, says Dr. Amy McMichael, MD, FAAD, a board-certified dermatologist and professor of dermatology at Wake Forest University School of Medicine.

If you’re facing brittle, easily broken nails, biotin supplements may be used as a short-term treatment, McMichael says. But, if you are considering taking any kind of supplement for nail health, always have a conversation with your board-certified dermatologist first, McMichael underscores.

What is the downside of taking biotin?

Biotin is a water soluble vitamin, meaning “when there's an excess supply, it's excreted through the urine,” says Hemeida. Overall, biotin is considered to be “a very safe vitamin."

More: What vitamins should you take? Why experts say some answers to this are a 'big red flag.'

However, “there is too much of a good thing when it comes to biotin, because it can prevent you from accurately diagnosing other important issues,” and it may interfere with the results of certain laboratory tests, Hemeida warns.

“For that reason, we now recommend to patients to really not take biotin unless they are biotin-deficient, and that is proven by their physician,” McMichael says.

This article originally appeared on USA TODAY: What does biotin do? Benefits and potential risks